The embodiments described herein relate generally to turbine buckets, and more particularly, to methods and apparatus for use in assembling a segmented airfoil of a turbine bucket.
At least some known gas turbine engines include a combustor, a compressor, and/or turbines that include a rotor disk that includes a plurality of rotor blades, or buckets, that extend radially outward therefrom. The plurality of rotating turbine blades or buckets channel high-temperature fluids, such as combustion gases or steam, through either a gas turbine engine or a steam turbine engine. The root segments of at least some known buckets are coupled to the disk with a dovetail that is inserted within a dovetail slot formed in the rotor disk. Because such turbine engines operate at relatively high temperatures and may be relatively large, the operating capacity of such an engine may be at least partially limited by the materials used in fabricating the buckets and/or the length of the airfoil portions of the buckets. To facilitate enhanced performance, at least some engine manufacturers have increased the size of the engines, thus resulting in an increase in the length of the airfoil portion of the buckets. Such an increase can require the size of the dovetails and the dovetail slots to be increased to ensure the longer buckets are retained in position.
Moreover, the tip portion of the airfoil of the rotor blades may be exposed to significantly higher temperatures than the root portion of the same airfoil, which may cause the blade tips to prematurely fail over time. Such failures can require replacement of the damaged turbine bucket. In the case of a “blisk”, such failures can require expensive replacement and/or refurbishment of the entire “blisk”. As such, a turbine bucket with a repairable and/or replaceable airfoil tip portion could reduce maintenance costs and reduce the operational issues related to ever-increasing lengths of the airfoil portion of turbine buckets.